The concept of gas valves is well known in the art. Gas valve typically comprises an inlet, an outlet, and a chamber with a diaphragm located within the chamber. The chamber is normally vented to an outside atmosphere through an air vent to allow for the movement of the diaphragm to thereby regulate the flow of gas.
As the air vent is located on the top of the gas valve the gas valve air vent is often times susceptible to clogging from insects, dust and if used outdoors, also to snow, ice, and/or other foreign particles or fluids. Cloggage of the gas valve air vent can prevent the gas valve from operating properly.
To prevent gas from escaping in the even that the diaphragm of a gas valve ruptures, it is known in the art to mount a vent limiter to the air vent of the gas valve. The vent limiter allows air to slowly enter or leave the gas valve to allow for the movement of the diaphragm but blocks a rapid discharge of gas to the outside atmosphere if the diaphragm should rupture. An example of a vent limiter is the Vent Limiting Means (Product number 12A04/12A09) produced by Maxitrol® Company which is located in Southfield, Mich. 48037-2230. Although vent limiters such as the Maxitrol® Vent Limiting Means adequately prevents gas from escaping through the air vent in the event that the diaphragm ruptures, they are susceptible to clogging due to bugs, dust snow, ice, and/or other extraneous fluids.
It is also know in the art to protect the gas valves from clogging while preventing gas from escaping if the diaphragm ruptures. One such approach for protecting the clogging of gas valves is by attaching a weather cap over the entire gas valve. An example of the aforementioned device is shown in my U.S. Pat. No. 5,975,123, which discloses a one-piece weather cap that can be installed over a gas valve and frictionally held thereon to prevent bugs, dust snow, ice, and/or other extraneous fluids from obstructing the air vent in the valve. The one-piece weather cap of U.S. Pat. No. 5,975,123 can be used in conjunction with a vent limiter in a two-step process to not only protect the gas valve from outside elements but also to prevent the escape of gas in the event that the diaphragm ruptures. In the process one first attaches the vent limiter to the outlet of the gas valve vent and then installs the weather cap over the gas valve vent.
Other vent devices for protecting the clogging of gas valve vents includes devices that can be mounted to the air vent of the gas valve with the discharge end of the device pointing downward. One of advantages of using such devices is the device is a less costly way to reduce or prevent, rain, snow, bugs, and dust from blocking the gas valve vent while still allowing access to other regions of the gas valve. An example of the aforementioned device is a bent or U-shape tube having an end that can be inserted into the outlet of the gas valve vent with the second end of the tube facing downward so as to prevent rain and snow from entering the tube.
A further device that vents the gas valve to the outside atmosphere while preventing rain and snow from entering the gas valve or blocking the gas valve vent is sold by Maxitrol® Company, the Maxitrol vent protector (Product Number 13A15) has an end can be screwed into the outlet of the gas valve vent for protecting gas valve vent from rain, snow, dust or other foreign particles and insects.
However, a disadvantage of using devices such as the bent tubing or Maxitrol® Company's vent protector is that neither of the devices prevent gas from escaping from the gas valve through the air vent in the event that the gas valve diaphragm ruptures. In addition, using devices such as the bent tubing or Maxitrol® Company's vent protector also prevent the use of the vent limiter since the bent tubing and Maxitrol® Company's vent protector are mounted to the same gas valve vent as the vent limiter.